In the air freight industry, loaders are used to load cargo onto an aircraft and also to unload cargo from the aircraft. Such loaders are generally self-propelled vehicles with a load bed that is either capable of elevation from ground level to a position adjacent to the cargo bay door of an aircraft, or have a conveyor belt or other suitable lifting means for raising the cargo to the height of the cargo bay.
A particular type of loader is an aircraft catering vehicle. Aircraft catering vehicles are designed to allow rapid transfer of catering trolleys and other supplies to and from aircraft as part of the preparation of aircraft for flight (turnround). They typically consist of a van body mounted on a standard vehicle (e.g. truck) chassis. The van body is raised up to the aircraft door by a scissor lift mechanism. Access to and from the aircraft door is via a platform, which is often fitted with an extending section (bridge or bridge plate).
Current aircraft catering vehicles suffer from a number of drawbacks. For example, the much larger size of aircraft in use today means that they carry a far larger number of passengers, meaning that a greater number of catering trolleys must be loaded and unloaded at every turnround. This either necessitates servicing of one aircraft with multiple aircraft catering vehicles, which is inefficient in terms of capital costs and fuel consumption, or multiple loading and unloading visits by a single aircraft catering vehicle, which is also inefficient in terms of fuel consumption and causes undesirable delay. For these reasons, an aircraft catering vehicle having a higher load capacity in terms of the number of catering trolleys is desirable.
However, the physical size of aircraft catering vehicles is constrained by a number of factors.
In principle, it is possible to increase the width of the body of the vehicle. However, because of the need for aircraft catering vehicles to travel on public highways, they must comply with local legislation which limits the width of goods vehicles to below 2.55 meters in most European countries. Additionally, the majority of airports have width restrictions which apply to vehicles travelling airside. Finally, a wider bodied vehicle would require specialist bespoke chassis to be manufactured at significant cost making the vehicle un-economic.
Increasing the length of the vehicle is also an option. Existing vehicles are circa 9 meters in length. There is significant scope for building longer trucks, potentially up to 18.45 m in length. However, airports generally require that vehicles have a turning circle of less than 33 feet (10 meters). This would require any vehicle much larger than 9 meters to be articulated with rear steering axles. Articulated vehicles are not permitted to engage with aircraft doors to load/unload them as there is deemed to be a risk of damaging the aircraft.
The final option would be to increase the height of the vehicle. Although there is no specific height requirement dictated about vehicles operating on an airfield, from a practical view point, the presence of bridges and other obstacles dictates an overall height of 4 meters or less in order to allow the vehicle to move around the airport uninhibited. Additionally, for the vehicle to have applications outside of the UK, typically regulations in other jurisdictions mandate that vehicles must not exceed 4 meters in height. A further problem with high vehicles is that the centre of gravity becomes elevated, meaning that the stability of the vehicle is reduced.
An additional constraint imposed on aircraft catering vehicles is that there be a suitable working height for operatives to enter the loading area to load and unload catering trolleys.
The present invention seeks to address these and other problems of the prior art.